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WO1997050061A1 - Procede et dispositif pour mesurer des proprietes magnetiques de materiaux sous forme de feuilles - Google Patents

Procede et dispositif pour mesurer des proprietes magnetiques de materiaux sous forme de feuilles Download PDF

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Publication number
WO1997050061A1
WO1997050061A1 PCT/EP1997/003280 EP9703280W WO9750061A1 WO 1997050061 A1 WO1997050061 A1 WO 1997050061A1 EP 9703280 W EP9703280 W EP 9703280W WO 9750061 A1 WO9750061 A1 WO 9750061A1
Authority
WO
WIPO (PCT)
Prior art keywords
magnetic
signal
detector
electrical
signals
Prior art date
Legal status (The legal status is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the status listed.)
Ceased
Application number
PCT/EP1997/003280
Other languages
German (de)
English (en)
Inventor
Dieter Stein
Lothar SCHÜTT
Current Assignee (The listed assignees may be inaccurate. Google has not performed a legal analysis and makes no representation or warranty as to the accuracy of the list.)
Giesecke and Devrient GmbH
Original Assignee
Giesecke and Devrient GmbH
Priority date (The priority date is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the date listed.)
Filing date
Publication date
Application filed by Giesecke and Devrient GmbH filed Critical Giesecke and Devrient GmbH
Priority to DE59710214T priority Critical patent/DE59710214D1/de
Priority to AT97930382T priority patent/ATE242523T1/de
Priority to EP97930382A priority patent/EP0846310B1/fr
Priority to AU34359/97A priority patent/AU3435997A/en
Priority to JP10502334A priority patent/JPH11511883A/ja
Priority to US09/011,747 priority patent/US6229306B1/en
Publication of WO1997050061A1 publication Critical patent/WO1997050061A1/fr
Anticipated expiration legal-status Critical
Ceased legal-status Critical Current

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Classifications

    • G—PHYSICS
    • G01—MEASURING; TESTING
    • G01V—GEOPHYSICS; GRAVITATIONAL MEASUREMENTS; DETECTING MASSES OR OBJECTS; TAGS
    • G01V3/00—Electric or magnetic prospecting or detecting; Measuring magnetic field characteristics of the earth, e.g. declination, deviation
    • G01V3/08—Electric or magnetic prospecting or detecting; Measuring magnetic field characteristics of the earth, e.g. declination, deviation operating with magnetic or electric fields produced or modified by objects or geological structures or by detecting devices
    • G01V3/10—Electric or magnetic prospecting or detecting; Measuring magnetic field characteristics of the earth, e.g. declination, deviation operating with magnetic or electric fields produced or modified by objects or geological structures or by detecting devices using induction coils
    • G01V3/104—Electric or magnetic prospecting or detecting; Measuring magnetic field characteristics of the earth, e.g. declination, deviation operating with magnetic or electric fields produced or modified by objects or geological structures or by detecting devices using induction coils using several coupled or uncoupled coils
    • G01V3/108—Electric or magnetic prospecting or detecting; Measuring magnetic field characteristics of the earth, e.g. declination, deviation operating with magnetic or electric fields produced or modified by objects or geological structures or by detecting devices using induction coils using several coupled or uncoupled coils the emitter and the receiver coils or loops being uncoupled by positioning them perpendicularly to each other
    • G—PHYSICS
    • G07—CHECKING-DEVICES
    • G07D—HANDLING OF COINS OR VALUABLE PAPERS, e.g. TESTING, SORTING BY DENOMINATIONS, COUNTING, DISPENSING, CHANGING OR DEPOSITING
    • G07D7/00—Testing specially adapted to determine the identity or genuineness of valuable papers or for segregating those which are unacceptable, e.g. banknotes that are alien to a currency
    • G07D7/04—Testing magnetic properties of the materials thereof, e.g. by detection of magnetic imprint

Definitions

  • the invention relates to a method and a device for measuring magnetic properties of sheet material, such as. B. banknotes.
  • Such a device is known from DE 4022739.
  • the device has at least one measuring head with at least two pole pieces, which are arranged such that they form a measuring gap.
  • the magnetic signals generated by the magnetic properties of the sheet material at the measuring gap are converted into electrical signals by a detector on at least one of the pole pieces.
  • one pole piece is made of permanent magnetic material and the other pole piece is made of soft magnetic material.
  • the magnetic field generated by the material of the permanent magnetic pole piece is chosen so large that the soft magnetic material of the other pole piece has a suitable magnetic operating point. This measure ensures that even small magnetic signals at the measuring gap generate a sufficiently large electrical signal at the detector.
  • Banknotes in particular are generally low in the area of the printed image and e.g. high magnetic particle densities in the area of the security thread, so that electrical signals with low or high amplitudes are produced when measuring banknotes at the detector.
  • the object of the invention is to propose a method for measuring the magnetic properties of sheet material, which reliable signals as well as with a high magnetic particle density.
  • the basic idea of the invention is essentially to amplify the electrical signals generated by the detector of a measuring head in a specific signal range in such a way that the electrical signals generated by the regions with a lower magnetic particle density are amplified with a lower amplitude than those from the Areas of high magnetic particle density produced electrical signals with higher amplitudes.
  • the signal area is divided into at least two signal areas, each of which is constantly amplified. The amplification in the area for signals of lower amplitude is greater than in the adjacent signal area.
  • the signal area is preferably divided into at least three areas, each of which is constantly amplified.
  • the gain in the two outer areas is selected to be the same and the gain in the middle area is greater than the gain in the outer areas.
  • the electrical signal is preferably shifted by a constant value before amplification, so that the zero point of the signal range lies in the middle of the middle range.
  • An advantage of the method is that the low amplitude electrical signals generated by the low particle density regions are in the central region of the signal region and are strongly amplified, while the electrical signals generated by the high particle density regions Signals with a high amplitude fall into the two outer areas of the signal area and are amplified less than the electrical signals with a low amplitude.
  • the amplitudes of the electrical signals at the amplifier output are thus distributed more evenly over the output area of the amplifier and can then be optimally processed, for example, by a downstream analog-digital converter.
  • a suitable shift of the electrical signal of the detector can amplify both positive and negative amplitudes.
  • a measuring head known from DE 40 22 739 can be used, for example, to convert the magnetic properties of the sheet material into electrical signals.
  • a preferred embodiment of a device for carrying out the method has at least one measuring head with at least two pole shoes, which are magnetically decoupled, each having a detector and preferably soft magnetic material. Means are also provided for generating a magnetic field that is constant over time and perpendicular to the detector plane, the strength of the magnetic field being different at each detector. The strength of the temporally constant magnetic field is preferably selected such that the soft magnetic material of a pole piece has a suitable magnetic operating point.
  • An advantage of the preferred embodiment is that, due to the asymmetrically constructed measuring head, the signals generated and amplified by the detectors each have different symmetries when measuring soft magnetic particles with low remanence and hard magnetic particles with high remanence. This allows differentiate whether the measurement involves particles of low or high remanence.
  • means for generating a defined, time-varying, magnetic signal are provided in the measuring gap of the measuring head.
  • An electrical conductor is preferably provided here, through which a defined, time-variable, electrical signal is passed.
  • the amplification of the amplifier can now be changed, for example, in such a way that the electrical signals measured at the amplifier output are adapted to a certain value.
  • the electrical signals measured at the amplifier output can also be adapted to a specific value by suitable standardization of the electrical signals. This procedure can eliminate undesirable changes in the gain, e.g. caused by temperature influence or also by wear of the measuring head.
  • 1 is a schematic diagram of the preferred embodiment of the invention, 2 schematic representation of a device according to the invention,
  • Fig. 4 shows a schematic representation of the amplified electrical
  • FIG. 5 is a schematic diagram of a measurement of hard magnetic or soft magnetic particles
  • FIG. 1 shows a schematic diagram of the preferred embodiment of the invention.
  • the sheet material 10 and a plurality of measuring heads 20 arranged as an array are shown in a perspective view in FIG. 1 a, in a side view in FIG. 1 b and in a top view in FIG. 1 c.
  • Each measuring head 20 has two pole shoes 21 and 22, which are magnetically decoupled and each have a detector 23 and 24, respectively.
  • Suitable detectors 23 and 24 are, for example, coils, Hall probes or magnetically sensitive resistors.
  • a permanent magnet 25 is provided. In order to achieve a good interaction between the permanent magnet 25 and the pole piece 21, these are directly connected to one another, so that the magnetic field generated by the permanent magnet 25 can penetrate well the material of the pole piece 21.
  • the pole shoes 21 and 22 preferably have soft magnetic material.
  • the strength of the magnetic field of the permanent magnet 25 is selected so that the soft magnetic material of the pole piece 21 has a suitable magnetic working point.
  • the magnetic field of the permanent magnet 25 in the pole shoe 22 is substantially smaller than in the pole shoe 21, so that the pole shoe 22 has no suitable magnetic working point.
  • a shield (not shown here) can additionally be provided around the pole shoe 22, so that the strength of the magnetic field of the permanent magnet 25 in the pole shoe 22 is as low as possible.
  • the pole pieces 21 and 22 are arranged such that they form a measuring gap M and transmit magnetic signals at the measuring gap perpendicular to the detector plane of the respective detector 23 or 24.
  • the detectors 23 and 24 then convert these magnetic signals into electrical signals.
  • an electrical conductor 26 can be provided in the measuring gap M for generating a time-varying magnetic signal.
  • the detectors 23 and 24 are preferably connected to one another, so that each measuring head 20 only generates an electrical signal. By connecting detectors 23 and 24 in the opposite direction, external magnetic influences acting on the pole shoes 21 and 22 are minimized since the electrical signals of the detectors 23 and 24 essentially cancel each other out when the connection is in the opposite direction.
  • the electrical signals of the detectors 23 and 24 can also be conducted separately from the measuring head 20.
  • the signals can then optionally be amplified with a separate amplifier and processed further separately.
  • a plurality of magnetic heads can be arranged as an array, the measuring gaps of the individual measuring heads being aligned parallel to one another. With such an arrangement, several traces of the sheet material 10 can be measured simultaneously.
  • a single appropriately dimensioned permanent magnet 25 can be used here to generate the magnetic field which is constant over time.
  • the device In addition to a measuring head 20, which can either be designed according to the prior art or preferably as described above, the device also has an amplifier 30 which amplifies the electrical signals of the measuring head 20.
  • the amplifier 30 has a preamplifier 40, an offset generator 50, a dynamic amplifier stage 60 and a calibration device 70.
  • the magnetic properties of the sheet material are first detected at the measuring gap of the measuring head 20 and then converted by the detectors 23 and 24 of the measuring head 20 into electrical signals of a certain signal range.
  • This Electrical signals then reach the amplifier 30 at point A.
  • the electrical signals are generally initially uniformly amplified by a pre-amplifier 40.
  • the electrical signal generated by the preamplifier 40 at point B is preferably shifted by a constant value by means of an offset generator 50 and can thus be adapted to the characteristic of the subsequent dynamic amplifier stage 60.
  • the characteristic curve of the dynamic amplifier stage 60 is shown in FIG. 3.
  • the strength of the electrical signals Sc at point C is plotted on the X axis.
  • the strength of the electrical signals S D after the dynamic amplifier stage 60 is shown in point D on the Y axis.
  • the signal area preferably has three areas Bi, B 2 and Bs with constant. Reinforcement Vi or V2. In the two outer areas B 2 and B3, the gain is the same, here Vi. In the central area Bi, the gain V 2 is greater than the gain Vi in the outer areas B 2 and B3.
  • the signal area can also be divided into more than three areas.
  • the reinforcements are chosen the same in symmetrical areas, i.e. the reinforcement in the two outermost regions, in the two second regions from the outside, etc., is the same in each case, while, for example, the reinforcement in the outermost region can differ from that in the second region from the outside.
  • the gain of the middle area can be chosen freely.
  • the special characteristic of the dynamic amplifier stage 60 ensures that electrical signals with a low amplitude are strongly amplified in the central region Bi of the signal region, while the electrical signals are amplified 97/50061 PC17EP97 / 03280
  • the amplified electrical signals of a measurement of a sheet material are shown schematically in FIG. 4a, for example, a banknote is shown as sheet material which has a low magnetic particle density in the area of the printed image shown in gray, while the magnetic particle density is high in the area of the security thread shown in broken lines.
  • 4b shows the electrical signal generated by the banknote at point B of amplifier 30 over the length L of the banknote.
  • the electrical signal shows both positive and negative amplitudes.
  • the amplitudes are very low in the area of the printed image, while they are very high in the area of the security thread. In reality, the ratio between high and low amplitudes can be considerably less favorable than the ratio shown here for reasons of clarity.
  • the electrical signal SB at point B is first shifted by the offset generator 50 by two units to positive values, so that the zero point of the signal area is in the middle of the middle area the dynamic amplifier stage 60.
  • the resulting signal Sc is then amplified at point C by the dynamic amplifier stage 60 with the characteristic curve shown in FIG. 3.
  • the electrical signal SD resulting therefrom at point D is shown in FIG. 4c.
  • the amplitude of the electrical signal S D at point D of the amplifier 30 is thus distributed much more uniformly over the output region of the amplifier than the electrical signal SB at point B and the signal curve can be seen more clearly.
  • the electrical signal SD at point D can now be optimally processed, for example, by an analog / digital converter 80.
  • the digital output values are now essentially distributed over the entire value range between 0 and 255.
  • a direct conversion of the electrical signal Sc at point C would essentially only provide an average value and the extreme values 0 and 255. Information about the course of the electrical signal Sc would be lost in such a conversion.
  • the digital output values generated by the analog / digital converter 80 can then be transmitted, for example, to a measured value processing device 90, which then compares, for example, the digital values obtained for checking the sheet material with stored digital values.
  • FIG. 5 shows an enlarged detail of FIG. 1b and basically shows the measurement of soft magnetic or hard magnetic particles.
  • the hard magnetic particles 11 are all magnetized with the south pole shown in white in the direction of the pole shoes 21 and 22.
  • the magnetization of the hard magnetic particles can be carried out, for example, before the measurement by a strong permanent magnet (not shown here) or the permanent magnet 25.
  • the course of the magnetic field H is shown schematically.
  • the strength of the magnetic field H is proportional to the density of the lines shown.
  • the strength of the magnetic field H is therefore the strongest at the permanent magnet 25.
  • the strength of the magnetic field H is significantly lower in the region of the pole shoe 22.
  • the magnetization of the hard magnetic particles in the region of the pole shoes 21 and 22 remains essentially unaffected by the local strength of the magnetic field H.
  • the magnetization of the soft magnetic particles 12 depends on the local strength of the magnetic field H. In the area of the pole piece 21, the magnetization of the soft magnetic particles is strong due to the presence of a relatively strong magnetic field H, while in the area of the pole piece 22 the magnetization of the soft magnetic particles 12 disappears almost completely, since there the magnetic field H has a much lower strength.
  • FIG. 6 schematically shows the signal symmetry of the electrical signals generated at the detectors 23 and 24, as is generated by a narrow area with hard magnetic particles as the sheet material 10 is transported past.
  • the strength of the magnetic field H is plotted against time in FIG. 6a.
  • the hard magnetic area is located above the pole piece 21 and since it is magnetized in the opposite direction to the magnetic field H, the magnetic field H is weakened.
  • this process takes place in the detector 24 of the pole piece 22. Since the magnetization of the hard magnetic area is constant over the entire time, an equal electrical signal should be generated at the detectors 23 and 24 with the same permeability ⁇ in the pole pieces 21 and 22, as shown in FIG. 6b .
  • the amplitude of the electrical signal S is proportional to the change in the magnetic field over time (S ⁇ ⁇ dH / dt).
  • the electrical signal of the detector 23 was additionally inverted for the reasons mentioned above.
  • the permeability ⁇ in the pole pieces 21 and 22 differs due to the different local strength of the magnetic field H. Only the material of the pole piece 21 has an optimal permeability ⁇ (H) and thus an optimal working point, so that the detector 23 generates an electrical signal with a high amplitude. As shown in FIG. 6c, the electrical signal generated at the detector 24 has a lower amplitude.
  • FIG. 7 shows the signal curves analogous to FIG. 6 for a narrow area with soft magnetic particles. Since the magnetization of the soft magnetic area in the area of the pole piece 22 has almost completely disappeared, as shown in FIG. 7 a, there is a substantially smaller change in the magnetic field H at time t 2 and thus also with the same permeability ⁇ in the pole pieces 21 and 22 a significantly lower electrical signal at the detector 24 according to FIG. 7b.
  • a calibration device 70 is provided in the amplifier 30.
  • the calibration device 70 For calibration, the calibration device 70 generates a defined electrical signal which is fed in and amplified at points A, B or C of the amplifier.
  • the electrical signal SD at point D is measured by the calibration device 70 and compared with target values stored in the calibration device 70. On the basis of this comparison, the gain of the dynamic amplifier stage 60 is changed in such a way that the electrical signals SD measured by the calibration device 70 at point D correspond to the desired values stored in the calibration device 70 and corresponding to the defined electrical signals generated by the calibration device 70.
  • FIG. 8 An exemplary signal curve for a defined electrical signal from the calibration device 70 is shown in FIG. 8.
  • Calibration device 70 preferably generates an electrical signal that changes over time and covers the entire signal range. An example of such a signal is shown in FIG. 8a over time. If this electrical safety If, for example, signal is fed in at point B, the calibration device 70 at point D should measure the electrical signal curve SD shown in FIG. 8b. Corresponding deviations from the target values can be compensated for by the change in the gain of the amplifier stage 60 described above.
  • the calibration device 70 may change the shift in the offset generator 50 or the gain in the preamplifier 40.
  • the shape of the defined electrical signal generated by the calibration device 70 is shown as a sawtooth in FIG. 8a, but can in principle be chosen as desired.
  • the calibration device 70 generates a defined electrical signal and feeds it into points A, B or C of the amplifier 30, for example.
  • the digital signals amplified by the amplifier 30 and converted by the analog / digital converter 80 are then standardized in the measured value processing device 90 to the expected digital setpoints.
  • the normalization constants required for this can be calculated, for example, as a quotient of the expected digital setpoints and the converted digital signals and stored in corresponding tables in the measured value processing device 90.
  • the calibration device 70 By feeding the electrical signals generated by the calibration device 70 at points A, B or C of the amplifier 30, only undesired changes in the gain are eliminated.
  • the calibration device 70 In order to additionally eliminate undesired changes, for example due to wear of the measuring head 20, the calibration device 70 generates a defined, time-varying electrical signal which is transmitted through the electrical conductor 26 is passed in the measuring gap M of the measuring head 20.
  • a defined magnetic signal is generated in the measuring gap of the measuring head 20 by this electrical signal.
  • this electrical signal can then be adapted to a predetermined setpoint either by appropriate changes in the amplifier 30 or by standardization by the measured value processing device 90.

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  • Physics & Mathematics (AREA)
  • Life Sciences & Earth Sciences (AREA)
  • General Physics & Mathematics (AREA)
  • Engineering & Computer Science (AREA)
  • Remote Sensing (AREA)
  • Environmental & Geological Engineering (AREA)
  • Electromagnetism (AREA)
  • Geology (AREA)
  • General Life Sciences & Earth Sciences (AREA)
  • Geophysics (AREA)
  • Investigating Or Analyzing Materials By The Use Of Magnetic Means (AREA)
  • Inspection Of Paper Currency And Valuable Securities (AREA)
  • Measuring Magnetic Variables (AREA)
  • Measurement Of Length, Angles, Or The Like Using Electric Or Magnetic Means (AREA)

Abstract

L'invention concerne un procédé pour mesurer les propriétés magnétiques de matériaux sous forme de feuilles, qui permet de fournir des signaux fiables aussi bien lorsque la densité particulaire magnétique des matériaux sous forme de feuilles est faible ou élevée. Dans un premier temps, une tête de mesure convertit les propriétés magnétiques du matériau sous forme de feuille en signaux électriques. Les signaux électriques produits par la tête de mesure sont amplifiés dans une plage de signal déterminée, de manière telle que les signaux électriques de moindre amplitude produits par les zones de densité particulaire magnétique plus faible du matériau sous forme de feuille sont amplifiés plus intensément que les signaux électriques de plus grande amplitude produits par les zones de densité particulaire magnétique plus forte du matériau sous forme de feuille. A cet effet, la plage de signal est divisée en au moins trois zones dont chacune est amplifiée de manière continue. L'amplification qui intervient dans les deux zones extérieures est identique et celle qui intervient dans la zone centrale est plus importante que celle des zones extérieures. Le signal électrique est de préférence déphasé d'une valeur constante, de manière que le point zéro de la plage de signal se situe au milieu de la zone centrale.
PCT/EP1997/003280 1996-06-24 1997-06-23 Procede et dispositif pour mesurer des proprietes magnetiques de materiaux sous forme de feuilles Ceased WO1997050061A1 (fr)

Priority Applications (6)

Application Number Priority Date Filing Date Title
DE59710214T DE59710214D1 (de) 1996-06-24 1997-06-23 Verfahren und vorrichtung zur messung magnetischer eigenschaften von blattgut
AT97930382T ATE242523T1 (de) 1996-06-24 1997-06-23 Verfahren und vorrichtung zur messung magnetischer eigenschaften von blattgut
EP97930382A EP0846310B1 (fr) 1996-06-24 1997-06-23 Procede et dispositif pour mesurer des proprietes magnetiques de materiaux sous forme de feuilles
AU34359/97A AU3435997A (en) 1996-06-24 1997-06-23 Method and device for measuring the magnetic properties of sheet materials
JP10502334A JPH11511883A (ja) 1996-06-24 1997-06-23 シート材料の磁気特性を測定する方法および装置
US09/011,747 US6229306B1 (en) 1996-06-24 1997-06-23 Method and apparatus for measuring magnetic properties of sheet material with both low and high magnetic particle density

Applications Claiming Priority (2)

Application Number Priority Date Filing Date Title
DE19625224.5 1996-06-24
DE19625224A DE19625224B4 (de) 1996-06-24 1996-06-24 Verfahren und Vorrichtungen zur Messung magnetischer Eigenschaften von Blattgut

Publications (1)

Publication Number Publication Date
WO1997050061A1 true WO1997050061A1 (fr) 1997-12-31

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Family Applications (1)

Application Number Title Priority Date Filing Date
PCT/EP1997/003280 Ceased WO1997050061A1 (fr) 1996-06-24 1997-06-23 Procede et dispositif pour mesurer des proprietes magnetiques de materiaux sous forme de feuilles

Country Status (9)

Country Link
US (1) US6229306B1 (fr)
EP (1) EP0846310B1 (fr)
JP (1) JPH11511883A (fr)
CN (1) CN1128425C (fr)
AT (1) ATE242523T1 (fr)
AU (1) AU3435997A (fr)
DE (2) DE19625224B4 (fr)
RU (1) RU2170948C2 (fr)
WO (1) WO1997050061A1 (fr)

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JP2002139392A (ja) * 2000-11-01 2002-05-17 Toshiba Corp 紙葉類の質感検出装置及び紙葉類の処理装置
US7378674B2 (en) 2002-04-30 2008-05-27 International Currency Technologies Corporation Magnetic verification system for bill acceptor
KR100735879B1 (ko) * 2003-03-14 2007-07-06 가부시키가이샤 히타치세이사쿠쇼 지엽류 취급장치
DE10326698A1 (de) * 2003-06-13 2004-12-30 Giesecke & Devrient Gmbh Prüfung elektrischer Leitfähigkeit und/oder magnetischer Eigenschaften von Sicherheitselementen in Sicherheitsdokumenten
JP4586151B2 (ja) * 2003-12-17 2010-11-24 日本電産サンキョー株式会社 紙葉類識別装置
CA2608908A1 (fr) * 2005-06-23 2006-12-28 Nv Bekaert Sa Authentification au moyen de caracteristiques de securite geometriques
ITMI20080261A1 (it) * 2008-02-19 2009-08-20 Fabriano Securities Srl Sensore di lettura di banconote, carte di sicurezza e simili, contenenti almeno un elemento di sicurezza.
DE102011110138A1 (de) * 2011-08-15 2013-02-21 Meas Deutschland Gmbh Messvorrichtung zum Messen magnetischer Eigenschaften der Umgebung der Messvorrichtung
DE102011120972A1 (de) 2011-12-13 2013-06-13 Giesecke & Devrient Gmbh Verfahren und Vorrichtung zur Prüfung von Wertdokumenten
JP5889697B2 (ja) * 2012-03-29 2016-03-22 グローリー株式会社 紙葉類磁性評価装置及び紙葉類磁性評価方法
DE102012013516A1 (de) 2012-07-06 2014-01-09 Giesecke & Devrient Gmbh Kalibrieren eines Magnetsensors
CN103839320A (zh) * 2012-11-23 2014-06-04 北京嘉岳同乐极电子有限公司 用于金融鉴伪机的磁传感器及其制作方法
DE102016015545A1 (de) 2016-12-27 2018-06-28 Giesecke+Devrient Currency Technology Gmbh Verfahren und Vorrichtung zum Detektieren eines Sicherheitsfadens in einem Wertdokument
DE102016015559A1 (de) 2016-12-27 2018-06-28 Giesecke+Devrient Currency Technology Gmbh Verfahren und Vorrichtung zum Detektieren eines Sicherheitsfadens in einem Wertdokument

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Publication number Publication date
US6229306B1 (en) 2001-05-08
EP0846310B1 (fr) 2003-06-04
RU2170948C2 (ru) 2001-07-20
DE59710214D1 (de) 2003-07-10
DE19625224A1 (de) 1998-01-02
ATE242523T1 (de) 2003-06-15
JPH11511883A (ja) 1999-10-12
CN1198231A (zh) 1998-11-04
AU3435997A (en) 1998-01-14
DE19625224B4 (de) 2005-07-28
EP0846310A1 (fr) 1998-06-10
CN1128425C (zh) 2003-11-19

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